1.\" Copyright (c) 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)join.1 8.3 (Berkeley) 4/28/95 36.\" $FreeBSD: src/usr.bin/join/join.1,v 1.3.2.5 2003/02/24 23:04:39 trhodes Exp $ 37.\" $DragonFly: src/usr.bin/join/join.1,v 1.4 2006/02/17 19:39:07 swildner Exp $ 38.\" 39.Dd April 18, 2002 40.Dt JOIN 1 41.Os 42.Sh NAME 43.Nm join 44.Nd relational database operator 45.Sh SYNOPSIS 46.Nm 47.Oo 48.Fl a Ar file_number | Fl v Ar file_number 49.Oc 50.Op Fl e Ar string 51.Op Fl j Ar fileno field 52.Op Fl o Ar list 53.Bk -words 54.Ek 55.Op Fl t Ar char 56.Op Fl \&1 Ar field 57.Op Fl \&2 Ar field 58.Ar file1 59.Ar file2 60.Sh DESCRIPTION 61The 62.Nm 63utility performs an 64.Dq equality join 65on the specified files 66and writes the result to the standard output. 67The 68.Dq join field 69is the field in each file by which the files are compared. 70The first field in each line is used by default. 71There is one line in the output for each pair of lines in 72.Ar file1 73and 74.Ar file2 75which have identical join fields. 76Each output line consists of the join field, the remaining fields from 77.Ar file1 78and then the remaining fields from 79.Ar file2 . 80.Pp 81The default field separators are tab and space characters. 82In this case, multiple tabs and spaces count as a single field separator, 83and leading tabs and spaces are ignored. 84The default output field separator is a single space character. 85.Pp 86Many of the options use file and field numbers. 87Both file numbers and field numbers are 1 based, i.e. the first file on 88the command line is file number 1 and the first field is field number 1. 89The following options are available: 90.Bl -tag -width indent 91.It Fl a Ar file_number 92In addition to the default output, produce a line for each unpairable 93line in file 94.Ar file_number . 95.It Fl e Ar string 96Replace empty output fields with 97.Ar string . 98.It Fl o Ar list 99The 100.Fl o 101option specifies the fields that will be output from each file for 102each line with matching join fields. 103Each element of 104.Ar list 105has the either the form 106.Ql file_number.field , 107where 108.Ar file_number 109is a file number and 110.Ar field 111is a field number, or the form 112.Ql 0 113.Pq zero , 114representing the join field. 115The elements of list must be either comma 116.Pq Ql \&, 117or whitespace separated. 118(The latter requires quoting to protect it from the shell, or, a simpler 119approach is to use multiple 120.Fl o 121options.) 122.It Fl t Ar char 123Use character 124.Ar char 125as a field delimiter for both input and output. 126Every occurrence of 127.Ar char 128in a line is significant. 129.It Fl v Ar file_number 130Do not display the default output, but display a line for each unpairable 131line in file 132.Ar file_number . 133The options 134.Fl v Ar 1 135and 136.Fl v Ar 2 137may be specified at the same time. 138.It Fl 1 Ar field 139Join on the 140.Ar field Ns 'th 141field of file 1. 142.It Fl 2 Ar field 143Join on the 144.Ar field Ns 'th 145field of file 2. 146.El 147.Pp 148When the default field delimiter characters are used, the files to be joined 149should be ordered in the collating sequence of 150.Xr sort 1 , 151using the 152.Fl b 153option, on the fields on which they are to be joined, otherwise 154.Nm 155may not report all field matches. 156When the field delimiter characters are specified by the 157.Fl t 158option, the collating sequence should be the same as 159.Xr sort 1 160without the 161.Fl b 162option. 163.Pp 164If one of the arguments 165.Ar file1 166or 167.Ar file2 168is 169.Dq - , 170the standard input is used. 171.Sh DIAGNOSTICS 172.Ex -std 173.Sh COMPATIBILITY 174For compatibility with historic versions of 175.Nm , 176the following options are available: 177.Bl -tag -width indent 178.It Fl a 179In addition to the default output, produce a line for each unpairable line 180in both file 1 and file 2. 181.It Fl j1 Ar field 182Join on the 183.Ar field Ns 'th 184field of file 1. 185.It Fl j2 Ar field 186Join on the 187.Ar field Ns 'th 188field of file 2. 189.It Fl j Ar field 190Join on the 191.Ar field Ns 'th 192field of both file 1 and file 2. 193.It Fl o Ar list ... 194Historical implementations of 195.Nm 196permitted multiple arguments to the 197.Fl o 198option. 199These arguments were of the form 200.Ql file_number.field_number 201as described 202for the current 203.Fl o 204option. 205This has obvious difficulties in the presence of files named 206.Ql 1.2 . 207.El 208.Pp 209These options are available only so historic shellscripts don't require 210modification and should not be used. 211.Sh SEE ALSO 212.Xr awk 1 , 213.Xr comm 1 , 214.Xr paste 1 , 215.Xr sort 1 , 216.Xr uniq 1 217.Sh STANDARDS 218The 219.Nm 220command conforms to 221.St -p1003.1-2001 . 222